The Effects of Pneumatic Stimulation on Human Tactile Perceptions

Pneumatic actuators are promising for wearable tactile interfaces, yet human perception of pneumatic stimulation is not well understood. This study examined how pressure and frequency affect tactile perception and emotional responses through three experiments. Experiment 1 measured the minimum perceivable pressure and just noticeable difference (JND). The perceptual threshold remained stable across low-frequency stimuli, while both upward and downward JNDs increased with pressure and frequency, indicating reduced sensitivity under stronger or faster stimulation. Experiment 2 evaluated perceived tactile intensity and found pressure to be the dominant factor, with frequency also contributing significantly. Experiment 3 examined emotional responses using the PAD model. Pressure and frequency jointly affected Pleasure and Arousal but minimally influenced Dominance. Moderate pressure and mid-range frequency (50 kPa, 5 Hz) produced the most positive, alert states; high-pressure, high-frequency stimulation (≥75 kPa, 10 Hz) generated unpleasant high-arousal responses; and low-pressure, low-frequency input (25 kPa, 1 Hz) led to low-arousal, negative affective states. These results offer quantitative and emotional insights that can inform the design of more realistic and expressive pneumatic haptic interfaces.